Partial Discharge Monitoring
Early Detection for Transformer Insulation Health
We supply Qualitrol’s industry‑proven Partial Discharge (PD) monitoring systems, designed to give power asset owners clear, real‑time visibility into transformer insulation health. PD activity is one of the earliest indicators of developing insulation faults, and early detection is essential to preventing costly failures. By providing proven UHF‑based monitoring equipment backed by Qualitrol’s global technology leadership, we help our customers strengthen operational reliability and support condition‑based maintenance strategies.

- 01 Application Overview
- 02 What We Solve For
Application Overview
Qualitrol PD monitoring systems are engineered for continuous, online use in power transformers, GIS, and other high‑voltage assets. These systems can be integrated during transformer manufacture with internal UHF sensors or installed later using external window or drain‑valve sensors. As a distributor, we provide complete solutions—hardware, software and installation support—that enable utilities to detect PD activity, classify defect types and correlate behaviour with load or switching events. This helps organisations monitor insulation health without taking equipment offline.
What We Solve For
Features & Functionality

UHF Detection
Qualitrol’s UHF sensors offer exceptional sensitivity, detecting PD activity down to −75 dBm or −80 dBm depending on the model. This enables significantly earlier fault indication compared to traditional or acoustic PD methods.
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Analysis & Visualization
Users can access advanced analysis tools—including PRPD, PRPS, point‑on‑wave, 2D/3D displays and trend analysis—to quickly evaluate PD severity, identify defect types and monitor changes over time.
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UHF sensors are available for internal installation, hatch‑cover mounting or drain‑valve retrofits. We support customers in selecting the right configuration and can provide custom sensor solutions for unique transformer designs.
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External noise and interference often affect conventional PD measurements. Qualitrol’s UHF systems incorporate noise‑gating antennas, filtering algorithms and protected enclosures to ensure stable and reliable measurements.
Functionality & Options
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Scalable architecture: 1–6 UHF sensors per OCU; expandable up to 24 channels.
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Real‑time PD trending: amplitude, discharge rate and correlation with load/OLTC operations.
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PD localization: time‑difference‑of‑arrival techniques supported when multiple sensors are installed.
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Remote monitoring and configuration: via secure Ethernet or fiber, with full software access.
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Automatic self‑check: built‑in channel diagnostics and alarm logging.
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Multiple communication protocols: IEC 61850, Modbus, SCADA relay outputs.
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Long‑term storage: up to 5–10 years of PD history for trending and reporting.
Key Technical Specifications
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UHF Sensor Inputs: 1–6 channels, expandable to 24.
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UHF Frequency Range: 300–2100 MHz.
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Sensitivity: −75 dBm to −80 dBm.
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Dynamic Range: 70 dB.
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Sampling Rate: 15,360 samples/s @ 60 Hz.
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Noise Channel: Dedicated external noise‑antenna input.
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Environmental Rating: IP66; operating range −25°C to +55°C; 5–95% humidity.
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Communications: Ethernet (RJ45/fiber), IEC 61850, Modbus.
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Data Storage: Solid‑state drive supporting multi‑year retention.
Our Projects featuring Insulect Transformers
Explore our project highlights to see where Insulect Transformers are making an impact.
For tailored advice on whether this solution suits your network, please connect with our team here.
Where you'll find our Disconnectors
You'll find Insulect-supplied and installed Disconnectors across Australia and New Zealand -- our locally built Insulect range and imported Sieyuan range.






Why Choose Insulect for
Partial Discharge Monitoring
UHF Technology
for Any Transformer
and Expertise
Services & Support
Insulect offers comprehensive services and support for the products we manufacture and specialise in, enhancing value for local utilities, major energy users, equipment manufacturers, and service operators.
Our local technical team provides exceptional support and expertise, ensuring quick response times and personalised service to tackle any challenges that may arise during project execution.
Our team utilises advanced technology and industry knowledge to develop innovative and efficient high-voltage switchgear solutions, customised to fit the unique requirements of each project.
We facilitate smooth procurement and logistics processes by sourcing from trusted, proven partners and coordinating timely deliveries, ensuring projects remain on schedule and within budget.
We are able to oversee every phase from concept to completion, providing comprehensive solutions that simplify complex projects and ensure successful outcomes.